I think that would be the difference between a managed flock and one that is not managed. Today's trend is that more~ and higher protein~ food equals good flock care and nothing could be further from the truth.
A chicken can only process so much protein before organ failure sets in, just like in a human, but far faster....they are just not equipped to ingest high proteins on a daily basis for any length of time. The high protein they receive out on free range in the form of bugs, grubs, lizards, snakes, etc. is combined with a lot of crude fiber as well, so it balances out. No one seems to care about balance any longer.
A chicken can only process so much protein before organ failure sets in, just like in a human, but far faster....they are just not equipped to ingest high proteins on a daily basis for any length of time. The high protein they receive out on free range in the form of bugs, grubs, lizards, snakes, etc. is combined with a lot of crude fiber as well, so it balances out. No one seems to care about balance any longer.